The initial 'pre-version' (known as 'Phase II software' in Wikipedia circles) was created by Magnus Manske, and used on all available Wikipedia versions from 25 January 2002. A 'Phase III software' became the first official MediaWiki, and was a substantial re-write by Lee Daniel Crocker; this was first used on the English Wikipedia on 20 July 2002. MediaWiki is compiled and written in PHP, and is probably the most widely deployed wiki engine software. Some would argue that a wiki should be more simplistic, with fewer features; but MediaWikis' design avoids many of the clutter / feature–creep problems that can appear in other mature wiki engines, and its success speaks for itself. MediaWiki has spawned many clones, the most notable being Wikia. MediaWiki is a highly developed, feature-rich software that is released for free under version 2 of the GNU General Public License (GNU GPL v2), and requires either MySQL 5.0.2+, PostgreSQL, or SQLite for data storage.

add /Special:Statistics at the end of the URL – eg. http://YourWikiURL.org/Special:Statistics (non-English language versions will automatically convert this to actual language). Dependent on software version, there is a number called "Content pages" or sometimes "pages that are probably legitimate content pages" -- use that lower number. Ignore the (often much larger) "all pages in the wiki, including redirects" number. We can also add MediaWiki listings to the https://S23.org/wikistats/mediawikis_html.php system which tracks various wiki statistics.

The Wikimedia Foundation, Inc. (WMF), founded 20 June 2003, is the wiki company and non-profitcharitableorganization responsible for a very large number (over 900 in total) of very active wikis, grouped together and known as 'projects'; as well as the wiki engine software initially developed by themselves, known as MediaWiki. The Foundations' major wiki projects include Wikipedia (encyclopedias), Wiktionary (dictionary and thesaurus), Wikiquote (quotations), Wikibooks (open content textbooks), Wikisource (free content primary and secondary source texts), Wikinews (news source), Wikiversity (open learning community), Wikispecies (free species directory), and many others as listed below. Most of these projects have separate wiki versions written in many different languages. There is also the Wikimedia Commons (shared repository for documents, images, videos, and other media files), Wikidata (central space knowledge base for data used on all WMF projects), and the Wikimedia Meta-Wiki (coordination of issues common to all Wikimedia projects). The Foundations' global reach is nurtured in its Incubator, where all new language versions for all projects are initiated and developed before being rolled out. Its most recent major project, Wikivoyage (a 'travelpedia'), was inducted to WMF in late 2012.